Ben Tordoff David W. Murray Reactive Control of Zoom while Fixating Using Perspective and Affine Cameras. 98-112 2004 26 IEEE Trans. Pattern Anal. Mach. Intell. 1 http://csdl.computer.org/comp/trans/tp/2004/01/i0098abs.htm db/journals/pami/pami26.html#TordoffM04